The macular function test is very important test... To understand the maula dis function and amount of disfunction. It is very useful for Central and colour vision.

2. Retina is the innermost Tunic of The Eyeball
& a Transparent Membrane.
 Thickness in different region:-
 Peripappilary area:- 0.56 mm
 Equator:- 0.18 – 0.20 mm
 Fovea:- 0.25 mm
 Foveola:- 0.13 mm
 Ora serrata:- 0.10 mm

4. THREE DISTINCT REGIONS OF RETINA
1. Optic disc :- Diameter – 1.5 mm
2. Peripheral Retina:-
Near periphery (1.5 mm) around macula.
Mid periphery 3 mm wide around near
periphery.
 Far periphery.
 Ora Serrata – temporally:- 2.1 mm wide
nasally:- 0.7 – 0.8 mm wide

5. 3. Macula Lutea
 Site:- temporal to optic disc at the post.
Pole
 Shape:- horizontally elliptical
 Diameter:- 5.5 mm
 Function:- photopic & colour vision
corresponds 15˚of visual field.

6.  Yellowish
 The coloration probably derives from the
presence of xanthophyll in the ganglion &
bipolar cells
 Yellow coloration remains for several hours
to few days in enucleated eyes kept in 4˚C

8. PARTS OF MACULA LUTEA
 Umbo:- tiny depression in centre corresponding
to foveal reflex
 Foveola:- diameter – 0.35 mm
thickness – 0.13 mm
 forms the central floor of fovea.
 Devoid of ganglion cell layer & contains cone
photoreceptors only.
 Corresponding 1˚of visual field.
 Colour:-reddish due to rich choroidal circulation
which shines through it.

9.  Fovea:- surrounds the foveola.
Situated 2 DD temporal to the disc margin &
0.8 mm below the horizontal meridian.
 The Foveal Avascular zone (FAZ):-
Located within the fovea but extends beyond
the foveola 500μ in diameter.
 Parafoveal zone:- 0.55 mm wide around the
fovea centralis
 Perifoveal zone:- 1.5 mm wide around the
parafoveal zone.

11. FOVEA
(LATIN- SMALL PIT OR DEPRESSION)
 Fully developed after 4 years.
 Diameter:- 1.85 mm
 Thickness:- 0.25 mm
 Situation:- at the post. Pole of globe, 4 mm
temporal to the OD.
 The downward slopping border of fovea which
meets the floor of the foveal pit is known as
clivus.
 Represents 5˚of the visual field.

12. LAYERS AT THE FOVEA
1. Retinal pigment epithelium
2. The layer of
photoreceptor- cones only
3. The external limiting
membrane
4. Outer nuclear layer-
contains the nuclei of
cones only
5. The inner fibres of the
photoreceptors-so called
Henle’s fibre layer
6. The internal limiting
membrane- thickest at the
fovea.

13.  Symptoms :
 Central vision impairment
 Metamorphopsia
 Micropsia
 Macropsia

14. MACULAR FUNCTION TESTS CLASSIFICATION
 MFT with clear media
 MFT with opaque media

15.  Visual acuity
 Contrast sensitivity
 Slit-lamp biomicroscopy
 Photostress test
 Colour vision
 Amsler grid
 Microperimetry
 FFA
 OCT

16.  Maddox rod test
 Foveal ERG
 VEP
 Laser interferometry
 Potential visual acuity meter test
 Entoptic phenomena
 B-scan

17.  VA is measured by the visual resolution of a
letter, symbol or a pattern under conditions of
maximal contrast.
 In pt’s with macular disease VA is frequently
worse when the pt looks through a pin-hole

19. PINHOLE TESTING
 Vision improves with
good macular function
 Acuity frequently worse
in macular disorder.

20.  Contrast sensitivity is a measure of the
minimum amount of contrast needed to
distinguish a test object.
 Indirectly assesses the quality of vision.
 Can detect early visual loss when VA is
normal.

22.  To detect retinal conditions like DR, ARMD &
other macular & optic nerve diseases.
 Optical conditions like refractive error,
refractive surgery, cataract & IOL
implantation & normal aging of the eye.

23. •Spatial frequency is the
number of dark light cycles
per visual angle.
•In macular diseases, there is
a marked impairment for the
intermediate & higher spatial
frequencies.

24. Is an effective test for
monitoring potential
decreases in contrast
sensitivity function over
time.

25. With a strong convex
lens affords excellent
vizualizaton of the
macula. (78D & 90D)

26.  Principle :
 The test involves exposing the macula to a
light source bright enough to bleach a
significant proportion of the visual pigments.
 Return of normal retinal function & sensitivity
depends on the regeneration of visual
pigments.

27.  Pathological states that affect the
photoreceptors, Bruch's membrane, chorio-
capillaries or can prolong visual recovery
time.
 No such prolonged is observed in diseases
affecting the neutral conducting pathways.

28. •Evaluates the 10˚ of visual field
centered on fixation.
•Used in screening and
monitoring macular diseases.
•Square 10*10 cm divided into400
5*5 mm squares to be held at
30cm.

30. PROCEDURE
 Reading glasses, cover 1 eye.
 Pt asked to see the central spot.
 Presence of abnormalities like blurred areas,
holes, distortions, or blank spots.
 Pt with maculopathy reports that the lines are
wavy whereas pt with optic neuropathy
remarks some lines are missing or faint.

33.  Colour vision is the function of three
populations of retinal cones.
 Blue (tritan) 414-424 nm
 Green (duetran) 522-539nm
 Red (proton) 549-570nm
 Normal person possess all these three cones
& called trichromate.

34.  Acquired macular diseases tends to produce
blue yellow defects & optic nerve lesions red
green defects.
 Deutran anomaly is the most commonly &
those subjects can not differentiate b/t red &
green colours.

35. COLOUR CONFUSION TESTS
•Ishihara charts is useful
as screening test.

36. HUE DISCRIMINATION TESTS
Farnsworth-Munsell 100
Hue test is the most sensitive
but seldom used.

37.  The principle of microperimetry rests on the
possibility to see –in real time- the retina
under examination (by infrared light) & to
project a defined light stimulus over an
individual, selected location.

38. SCANNING LASER OPHTHALMOSCOPE
MICROPERIMETRY
 SLO microperimetry was the 1st technique
which allowed to obtain a fundus related
sensitivity map.
 SLO uses a near infrared diode laser
(675nm) beam that rapidly scan the posterior
pole.
 The reflected light is detected by a confocal
photodiode & the digitized image is stored in
a computer.

40. FLUORESCEIN ANGIOGRAPHY
 Dark appearance of the fovea on FFA is
caused by FAZ & blockage of the choroidal
background by xanthophyll & dense RPE.
 FFA is a very useful tool in diagnosing
macular disorders e.g., diabetic maculopathy,
CSR & can reveals the functionality of the
lesion e.g. Ischemic maculopathy.

42. OPTICAL COHERENCE TOMOGRAPHY
 OCT it is non invasive non-contact imaging
that produce high resolution cross sectional
image.
 Useful in diagnosing macular disorders & to
delineate retinal layers & detect subtle
anatomical changes.

44.  Maddox rod
 Focal ERG
 VEP
 Laser interferometry
 Potential visual acuity meter test
 Entoptic phenomena
 Preferential hyperacuity perimeter (PHP)
 B-scan

45. MADDOX ROD TEST
•Simple & reliable test & can be
used in semi opaque media.
•Pt is asked to fixate light at a
distance of 1/3 through M.R. with
opposite eye occluded.
•Any breaks / holes; discoloration
/ distortion indicates a macular
lesion.

46. FOCAL ELECTRORETINOGRAM
 ERG is only abnormal when a large area of
retina is functionally impaired.
 Focal ERG needs a stimulus localizing to
one area without scattering of light to
stimulate the rest of the retina.

47. MAXWELL OPHTHALMOSCOPE (FOVEAL
FLICKERING SENSITIVITY)
 It is a hand foveal ERG
 It employs a 3-4 degrees
with flickering light focused
on the fovea with a 10
degrees annulus of constant
white light to desensitize
surrounding retina.

48. VISUALLY EVOKED POTENTIAL
 VEP measure of the electrical potential
generated in response to entire visual
pathway
 It represents integrity of entire visual pathway
from retina to occipital lobe so cannot
differentiate b/t macula, ON & cortical
pathology.

49.  Two types of stimulus either
by flash of light or by
patterned stimuli.
 If the issue is the V/A then
the amplitude is measured.
 If the issue is the lesion in
the visual pathway then the
latency is measured.

50. LASER INTERFEROMETRY
 Utilizes coherent white light or helium-neon
laser generated interference stripes or
fringes that are projected onto the retina
through the ocular media.
 Brightness increased in pt’s with dense
cataracts.
 The laser interferometer resolving power
converted to standard V.A.

51. LIMITATIONS
1. Subjective
2. Laser fringe vision>vision of letter acuity
3. Over predicts visual potential in amblyopes.

52. POTENTIAL VISUAL ACUITY METER TEST
 PAM introduced in 1983
 This is attached to slit lamp &
projects a reduced Snellen’s chart
via narrow beam of light through a
pinhole clear area in the cataract
towards the macular region.
 The resulting potential acuity is the
smallest line where pt was able to
read three characters.

53. LIMITATION
 Subjective
 Methods that require an alert & cooperative
pt & skilled compassionate examiner.
 But it is easier than laser interferometry.

54. ENTOPTIC PHENOMENA
 It is refer to visual perceptions that have their
origin in the structure of an observer’s eye.
 Three types are used for testing the macula
in opaque media:
1. Purkinje vascular E.P
2. Flying spot (blue field E.P)
3. Haidinger’s brushes

55. PURKINJE VASCULAR E.P
 The Purkinje’s vascular
entoptic test is a simple
method which elicits the
response by placing a
penlight against a closed
eyelid or the globe & moving it
back & forth, creating images
of the pt’s retinal vascular
tree.

56. FLYING SPOTS (BLUE FIELD ENTOPTIC
PHENOMENON)
 Blue field entoptoscopy relies on
the observation of leucocytes
flowing in the macular retinal
capillaries.
 The leucocytes appear as ‘Flying
Corpuscles’ when the retina is
diffusely illuminated with a bright
blue light.

57. HAIDINGER’S BRUSHES
 Subject looks at a surface
illuminated with blue light
through a polarizer.
 Hourglass shaped yellowish
brushes seen radiating from
the point of fixation.
 On rotating polarizer, brushes
rotate.

58.  Phenomenon caused by variations in
absorption of plane polarized light by
oriented molecules of xanthophyll pigment in
foveal retina.
 Used to sensitize the fovea in amblyopic
child with eccentric fixation.

59. ULTRASONOGRAPHY (B-SCAN)
 This gives a gross idea about anatomic
normalcy of the eye , & rules out pathologies
like vitreous haemorrhage, retinal
detachment, optic nerve anomalies, etc.
 Scanning does not offer any information on
macular function.

60. OPHTHALMOSCOPY
DO
IO

61. WATZKE-ALLEN TEST
 Done with 90D or 78D lens projecting a slit
beam over the centre of macula.
 Pt. with macular hole will report of broken
beam.

62. LASER AIMING BEAM TEST
 Helium-Neon laser spot of 50 micron is
projected at the centre of macula.
 Spot disappears in macular hole.